// Copyright (c) 2019, The Monero Project
//
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// permitted provided that the following conditions are met:
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// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
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//    used to endorse or promote products derived from this software without specific
//    prior written permission.
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#include <stdint.h>
#include <vector>
#include "cryptonote_basic/cryptonote_basic_impl.h"
#include "cryptonote_basic/cryptonote_format_utils.h"
#include "blockchain.h"
#include "tx_sanity_check.h"

#undef SISPOP_DEFAULT_LOG_CATEGORY
#define SISPOP_DEFAULT_LOG_CATEGORY "verify"

namespace cryptonote
{

  bool tx_sanity_check(Blockchain &blockchain, const cryptonote::blobdata &tx_blob)
  {
    cryptonote::transaction tx;

    if (!cryptonote::parse_and_validate_tx_from_blob(tx_blob, tx))
    {
      MERROR("Failed to parse transaction");
      return false;
    }

    if (cryptonote::is_coinbase(tx))
    {
      MERROR("Transaction is coinbase");
      return false;
    }
    std::set<uint64_t> rct_indices;
    size_t n_indices = 0;

    for (const auto &txin : tx.vin)
    {
      if (txin.type() != typeid(cryptonote::txin_sispop_key))
        continue;
      const cryptonote::txin_sispop_key &in_to_key = boost::get<cryptonote::txin_sispop_key>(txin);
      if (in_to_key.amount != 0)
        continue;
      const std::vector<uint64_t> absolute = cryptonote::relative_output_offsets_to_absolute(in_to_key.key_offsets);
      for (uint64_t offset : absolute)
        rct_indices.insert(offset);
      n_indices += in_to_key.key_offsets.size();
    }

    if (n_indices <= 10)
    {
      MERROR("n_indices is only " << n_indices);
      return true;
    }

    uint64_t n_available = blockchain.get_num_mature_outputs(0);
    if (n_available < 10000)
      return true;

    if (rct_indices.size() < n_indices * 8 / 10)
    {
      MERROR("unique indices is only " << rct_indices.size() << "/" << n_indices);
      return false;
    }

    std::vector<uint64_t> offsets(rct_indices.begin(), rct_indices.end());
    uint64_t median = epee::misc_utils::median(offsets);
    if (median < n_available * 6 / 10)
    {
      MERROR("median is " << median << "/" << n_available);
      return false;
    }

    return true;
  }

}
